One-pot synthesis of hyperbranched polyols and their effects as crosslinkers on HTPB-based polyurethane

Hyperbranched polyethers and hyperbranched poly(amino ester)s were synthesized through one-pot method, and characterized by fourier transform infrared spectroscopy, hydrogen nuclear magnetic resonance and thermogravimetry analysis (TGA). The as-obtained hyperbranched polyols with different molecular structure and sizes were used to crosslink hydroxyl-terminated polybutadiene-based polyurethane (PU). The PU was characterized by tensile test, dynamic mechanical analysis, TGA, and swelling properties. It was found that the crosslinker structure and size have great effects on the properties of the PU. Hyperbranched polyether cross-linked PU showed the best mechanical properties, which reached mechanical strength of 1.45 MPa with elongation at break of 617 % for the third generation with hard segment content of 26.8 % at 25 A degrees C.